Despite including sexual orientation as a source of disparity in Healthy People 2010, public health research on lesbian, gay, bisexual, and transgender populations has been lacking for the past 20 years, especially research that is not related to sexually transmitted diseases. This is of concern in prostate cancer treatment, with its manifold impacts on male quality of life. The very substantial body of research on the complex physical and psychosocial outcomes of treatment has traditionally assumed a heterosexual frame of reference. This is problematic when patient centered measures attempt to assess important changes in physical function associated with treatment. It is especially limiting when attention turns, as it has in recent years, to how changes in sexual function, which affect the majority of men who pursue active treatment, are appreciated in terms of how they affect the emotional and social well-being of men. All men are at risk of prostate cancer regardless of sexual orientation, but the experiences of gay men are unknown. Gay men may have difficulty dealing with heterosexually oriented urologists and oncologists, which may undermine the supportive dialog that facilitates satisfying treatment decisions and outcomes. To ensure the successful recruitment of gay men, many of whom are reluctant to self-identify as such in a traditional clinical setting, a variety of recruitment approaches will be used. Thus, this study will: (1) revise recently developed measures of physical and psychosocial domains of prostate cancer-related quality of life to better assess the experiences of gay men;and (2) assess post-treatment prostate cancer quality of life outcomes among gay men. These findings will inform the development of a quality of life model that takes into account the role of sexual orientation in prostate cancer treatment outcomes. PUBLIC HEALTH RELEVANCE: This study will continue a line of research developing a biopsychosocial model of the outcomes of treatment for prostate cancer that began with studies conducted by Talcott, Clark and their colleagues, along with many others. While these studies have shown that sexual and other bodily changes ramify broadly following prostate cancer treatment, our appreciation of these effects has been severely limited by sampling only heterosexual men. The proposed study seeks to remedy this deficit and develop a more comprehensive model of quality of life, based on inclusion of gay men, that can help inform clinicians performing prostate cancer diagnosis and treatment of quality of life outcomes that may be unique to gay men with localized prostate cancer.